. >>> meanwhile vice-president biden was in china shaking things up within hours of arriving there, the first stop on his two-day visit. it was the u.s. embassy where he told a group of mostly young people, chinese waiting in line for visas they should challenge their own government, saying innovation can occur only when you breathe free. >>> and back here at home, chicago police are reporting some welcome news tonight, what could be the fewest number of homicides since 1965. to the end of november there were 380 homicides reported and at this time last year the number was 474. after last year's surge in violence, the police launched a sweeping crime fighting initiative including more officers on control. >>> next here tonight, proof that generosity can change lives. it's part of our hidden america series. last may i reported on strawberry manks, a high school inside philadelphia. for five years considered one of the most dangerous schools in america. you met that night the valiant principle trying to save her students and her school. tonight we just want you to know how you helped as h